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PatchSiren cyber security CVE debrief

CVE-2026-42389 PowerDNS CVE debrief

CVE-2026-42389 is a medium-severity vulnerability with a CVSS score of 5.3, affecting PowerDNS Recursor systems, particularly those using versions 5.4.x. The vulnerability was published on 2026-06-25T14:16:39.653Z and last modified on 2026-10-25T23:10:00.167Z. The fix provides extra hardening for the 5.4.x branch by doing extra validation of incoming answers from authoritative servers. Defenders should assess exposure and prioritize verification of affected systems. The CVE record and NVD entry provide limited information about the vulnerability, with the vendor and product names not specified. To verify affected systems, defenders should review the supplied official advisory or N

Vendor
PowerDNS
Product
Recursor
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-25
Original CVE updated
2026-10-25
Advisory published
2026-06-25
Advisory updated
2026-10-25

Who should care

Defenders responsible for PowerDNS Recursor systems, particularly those using versions 5.4.x, should assess exposure and prioritize verification of affected systems.

Why it matters

Defenders should assess exposure and prioritize verification of affected PowerDNS Recursor systems, particularly those using versions 5.4.x, as the fix provides extra hardening for this branch. The vulnerability has a medium CVSS score of 5.3, and the fix provides extra validation of incoming answers from authoritative servers.

  • Verification of affected PowerDNS Recursor systems, particularly those using versions 5.4.x
  • Assessment of exposure to potential exploitation attempts
  • Prioritization of fix application for affected systems

Technical summary

The vulnerability is addressed by a fix that provides extra hardening for the 5.4.x branch of PowerDNS Recursor by doing extra validation of incoming answers from authoritative servers. The CVSS score is 5.3, and the CVSS vector is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Defensive priority

Defenders should assess exposure and prioritize verification of affected systems, particularly those using PowerDNS Recursor versions 5.4.x, as the fix provides extra hardening for this branch.

Recommended defensive actions

  • Assess exposure of PowerDNS Recursor systems, particularly those using versions 5.4.x
  • Verify if the fix has been applied to affected systems
  • Monitor for potential exploitation attempts

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability, with the vendor and product names not specified. The fix provides extra validation of incoming answers from authoritative servers, but details about affected versions and exploitation are not provided.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-42389 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-42389

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-42389 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-42389

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.